This is a Chronological list of parody covers of the National Geographic Magazine. Scott Shier has an excellent discussion on this topic in the Ephemera & Collectibles group. I felt that since these covers reflect an outside perception of the magazine I would provide a visual listing over time of these covers here to maybe provide some insight into how others see us.
Note, I am not only including actual covers and pages simulating covers in this listing but also posters, refrigerator magnets, trading cards and electronic images.
March 1936 - Pick & Hammer Club - Cover
May 1958 - Mad Magazine - Page
January 1966 - National Press Club - Cover
1967 - Vol. 4, No. 1 Lithopinion - Multiple Pages
1968 - Richard Pryor - Album Cover
May 1972(?) - Rainier Beer - Poster
December 1972 - National Lampoon - Page
1975 - Cracked Magazine - Back Cover
December 1975 - Playboy Magazine - Page
1976 - Dr. Fegg's - Book Page
1980 - Topps Wacky Products - Trading Card
August 1981 - Miss Piggy Cover Girl Fantasy Calendar - Page
February 1982 - Darkroom Magazine - Page
May 1983 - National Lampoon - Page
April 1986 - What's On (Scotland) - Cover
October 1989 - House and Garden Magazine - Menu
1992 - Nude & Natural - Cover
1995 - Waterworld - Movie Props (5)
2004 - Safely on the Sun - Magnet
April 2008 - Harvard Lampoon - Cover
March 2009 - Vanity Fair - Partial Page
October 24, 2010 (?) - The Portland Mercury - Cover
March 2011 - Mediavengers - eCover
Spring 2012 - Metro Times Chronicle - Cover
December 2012 - Mediavengers - eCover
May 2013 - Mediavengers - eCover
June 2014 - Sarah Palin - Magnet
September 2015 - New York Times - Editorial Cartoon
September 2015 - HBO: Real Time - 8 eCovers
February 2016 - HBO: Real Time - eCover
April 2016 - Michigan J. Frog - Magnet
Thanks Tom for adding these here in-group! Of course my fave is still always Snoopy & Beagle.
Also, I think I recall you mentioning the Dr. Fegg's one, but for the moment, I feel like that's the first time I saw it, in detail.
Dr. Fegg is the creation of Terry Jones and Michael Palin, both from Monty Python fame. Here is his portrait:
Note: I just added three more Nat Geo covers. These are from Mediavengers. They are based on the Marvel movies: Captain America, Avengers, and Thor.
Note: I have just added a cover for a parody merger between National Geographic and Cosmopolitan. It appears in the March 2009 issue of Vanity Fair.
Note: I just added eight (albeit small) parody covers from the September 11, 2015 episode of HBO's "Real Time with Bill Maher".
Note: I just added an entry for the cover of Richard Pryor's first comedy album (1968).
Note: I just added a parody cover from the February 12, 2016 episode of the HBO show "Real Time with Bill Maher".
Note: I just added an entry for the 1992 cover of vol. 11 no. 4 Nude & Natural Magazine.
Note: I just added two entries for the February 1982 Darkroom Photography and the October 1989 House & Garden magazines.
Note: I just added a parody cover from the 1981 "Miss Piggy Cover Girl Fantasy Calendar".
Note: I just added seven parody covers from non-standard sources, i.e. magnets, posters, trading cards, cartoons, and art.
1. 1967 - Lithopinion - Art
2. 1972(?) - Rainier Beer - Poster
3. 1980 - Topps Wacky Products - Card
4. 2005 - Safely on the Sun - Magnet
5. 2014 - Sarah Palin - Magnet
6. 2015 - Rupert Murdock - Cartoon
7. 2016 - Michigan J, Frog - Magnet
Note: I just added a cover for the October 24, 2010 (?) parody from The Portland Mercury as shown in the NGS publication, The Covers.